If you're building a SAAS product, I've struggled just like you.
You know what one of the biggest mistakes is?
Overengineering.
You don't have to over-engineer your product unless you're making a rocket ship.
The most successful SAAS products solve one specific problem, extremely well.
Don't get bogged down in the details, chase after the core value your product has to offer.
Make sure you're listening to your customer feedback. They'll tell you exactly what they need.
Start simple and make improvements as you go.
That's the key to building a successful SAAS product.